Two key cylinder lock



1954 w. J. OPOCENSKY TWO KEY CYLINDER LOCK Filed May 5, 1952 INVENTOR. M14440 J flflddinll) Patented Feb. 2, 1954 TWO KEY CYLINDER LOCK Willard J Opocensky, Glendale, Calif., assignor to Librascope, Incorporated, Glendale, Galif -a corporation of "California A plieatiun Ma 5, 1952, SerialNo. 286,065

rendered capable of performing only an unlocking operation; another rendered capable of performing only a locking operation; and perhaps a third provided with 'a key with master notching authorized to'perform both operations. Such locks are also useful in connection with the actuation of electrical switching devices, being used in such applications to compel a patrolling watchman, .''for instance, to operate a series of switches all in the same direction during one round when one key is carried and in the 0p- .posite direction during a later round when another key is carried. The embodiment of the present invention disclosed herein is adapted to the second "class of these uses, but it will be understood that the invention is in no way v limited to such a use.

The present invention contemplates the provision of a two-key lock in which a key with one type of notching will be capable of rotating the key plug within its sleeve in one direction, but

not in the other direction, while a key with a different notching will effect such rotation in the opposite direction, but not in the direction in which the first key is capable of rotating the plug. According to the present invention this is achieved by an extremely simple structural change in a conventional form of plate tumbler cylinder lock; such modification consisting essentially of the bevelling or chamfering of opposite sides of two of the plate tumblers of such a lock. Such chamfering causes one of the plate tumblers, which is intended to be left undisturbed by the insertion of one of the keys, to act as a ratchet when the key plug is rotated toward its chamfered side; permitting rotation in that direction, but preventing retrograde rotation. A second one of the plate tumblers chamfered on its opposite side acts as a ratchet in the same way when the plug is rotated in the opposite direction.

One form of lock embodying the present invention adapted for use as a switch operating device is illustrated in the accompanying drawings in which:

Figure 1 is a vertical median section through a lock switch embodying the present invention;

Figure 12 is a section at 'right angles to that of Figure l, on the plane of the line -2--'2 of Eigure 1;

Figure 3 is a similar section on the plane of the line 33 of Figure 1.

Figure 4 is a sectional view on an enlarged scale of the lock seen in Figure 1 showing the effect of one form of key in the lock;

Figure 5 is a section on line '5--5 of Figure 4';

Figure 6 is a section similar to'Figure 4 show"- ing the effect of the second form of key in the lock; and

Figure 7 is a section online 1-1 of Figure-6.

The combined lock and switch consists of an outer shell or housing to of the flared shape shown, intended to be mounted on a suitable support. The housing 10 is formed with an axial here within which is mounted a cylindrical sleeve l l fixed in the housing by, a clamp nut 12 on the threaded rear end of the sleeve. The

sleeve H is formed internally with a plurality 'of circumferentially spaced grooves 13 (Figure '3 the longitudinal edges of which are preferably undercut to provide opposed abutments M in each groove 1-3. The grooves are conventionally spaced at ninety degree angles.

The cylindrical sleeve ll forms the bearing for the rotatably mounted key plug !5. In the form illustrated, the inner end of plug I5 carries a spacer sleeve or washer l 5a, formed of insulating material, on which are mounted the oppositely extending radial contact arms lb of the switch. The metallic contact arms l6 and spacer 25a are fixed to the key plug l5 by a central clamp screw I'I threaded into the end of the key plug. At diametrically opposite sides, the housing It is formed with ledges [8 so proportioned as to provide stop shoulders l9 at the opposite ends limiting the arc of movement of the contact arms IE to ninety degrees. An insulating disk 20 which rests on an offset in the housing it and is fastened on the ledges l8 closes an inner chamber of the housing as shown. This disk carries appropriate contact buttons 2| on its inner surface adapted to be engaged by arms [B at their opposite limits of movement. The outer surface of disk 20 carries suitable binding posts as at 22, (Figure 1) electrically connected to buttons 2!.

The novel means for controlling operation of the switch resides in the cylinder lock. The lock is preferably of the conventional plate tumbler type and key plug 15 is shown with the usual axially offset key-way 23. This key-way is intersected by the usual series of vertical slots in the plug, each slot containing one of the series of spring-pressed tumblers which are adapted to be key actuated or controlled in the usual way. In their conventional form, the flattened angular ends 25 of the tumblers (Figure 3) will normally be projected into one of the grooves 13 forming a double interlock with the opposed shoulders I4 and preventing rotation of the key plug in either direction prior to insertion of a key.

With the improvement embodying the present invention, certain of the tumbler ends are so shaped as respectively to permit rotation of the plug in one direction only without retraction of that tumbler from the groove l3. One tumbler then controls clockwise rotation and another controls it counterclockwise.

This is accomplished by bevelling or inclining one side edge of one projecting end of a tumbler and the opposite side edge of another as indicated at 25 and 25, Figures 5 and 7, respectively. By this simple means each tumbler will yield to rotation of the plug in the direction of the bevel but present a single interlock with shoulder l4 preventing opposite rotation of the plug. A two-key lock is thus created.

In the practice of the invention at least two keys are used. Key A of Figure 4 is so notched as to retract all tumblers except that having the incline or bevel 25 of Figure 5. Its use will permit the plug to be rotated only counterclockwise from one locking groove l3 to the next, this being the extreme range of movement indicated on Figure 2 as determined by the stops at 19.

With key B of Figure 6 all tumblers except that having the bevel 26 of Figure '7 will be retracted and the plug will be rotatable only clockwise.

With the simple and eflicient multiple key lock above described use of two keys as described will insure that a control, such as an electric switch, can be operated only in one certain way. Obviously, a third key could be provided for withdrawing all tumblers should that be desired. Also, it is evident that modifications of the specific details described are possible within the scope of what is claimed.

What is claimed is:

1. A cylinder lock comprising a cylindrical sleeve formed with a plurality of circumferentially spaced internal grooves extending longitudinally thereof and formed to provide transversely opposed abutments, a key plug rotatably mounted in the sleeve, a series of spring-pressed tumblers with flattened angular ends normally projected into one of said grooves, certain of said tumbler ends having both sides edges shaped to interlock with the opposite abutments and prevent any rotation of the plug, other of said tumblers being shaped to form one vertical side edge having interlocking engagement with one abutment and an opposite beveled side edge shaped to ride over the opposite abutment, whereby withdrawal of all tumbler ends except one with a beveled side edge, by key insertion in the plug, will free the plug for rotation in only one direction.

2. A cylinder lock comprising a cylindrical sleeve formed with a plurality of circumferentially spaced internal seats presenting transversely opposed abutment shoulders, a key plug rotatably mounted in the sleeve, a plurality of spring-pressed tumblers carried by the plug having ends normally projected into said seats, one of said ends being shaped to interlock with only one of said shoulders and another of said ends being shaped to interlock with only the opposite shoulder, whereby the plug is adapted to be freed for rotation in one directionby use of one key and in the opposite direction by the use of another key.

- WILLARD J. OPOCENSKY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,036,764 Lowe Apr. 7, 1936 2,182,307 Behnke Dec. 5, 1939 2,580,882 Blohm Jan. 1, 1952 2,585,643 Feldmann Feb. 12, 1952 

